Carbon supply device for writing machines



April 12, 1949. 1 .JENSEN CARBON SUPPLY DEVICE FOR WRITING MACHINES Filed Oct. 12, 1945 2 Sheets-Sheet 1 April 12, 1949. JENSEN CARBON SUPPLY DEVICE FOR WRITING MACHINES 2 Sheets-Sheet 2 Filed oct. 12, 1945 11111111 1.. i111- llwi Patented Apr. 12, 1949 CARBON SUPPLY DEVICE FOR WRITING MACHINES Louis Jensen, Chicago, Ill., assigner to United Autographc Register Co., a corporation of Illinois Application October 12, 1945, Serial No. 621,950

1 Claim.

This invention relates to an attachment for a typewriting machine, such as a tabulating machine, wherein fresh carbon strips are advanced in interleaved relation with stationery strips led around the platen of a machine.

In writing machines using continuous form stationery, it is common to use one-time carbon which is interleaved and is coextensive with the stationery strips.

The primary object `of the present invention is to obtain many of the advantagesof one-time carbon without the waste, and to reduce the problem of disposing of carbon after it has been used in the machine.

Another object of the invention is to provide an attachment for a writing machine wherein a large supply of carbon is stored on rolls in rear of the platen and the carbon rolls are unwound at a much slower rate of travel than the stationery strips, so that fresh carbon is supplied at the printing line of the platen with a minimum of wastage.

Another object of the invention is to provide an automatic control for the unwinding of the carbon strips which will be operated in timed relation to the stationery feeding mechanism, but at a much slower rate of travel.

The invention is illustrated in a preferred embodiment in the accompanying drawings, in which- Figure 1 is a vertical side elevational view of the attachment with portions of the writing machine shown diagrammatically; and Fig. 2 is a front elevational view of the same.

In the embodiment illustrated, a tabulating machine has a rotary platen 3 around which stationery strips 4 are drawn .by a suitable feed mechanism. The stationery strips are shown provided with marginal perforations 5, which are engaged by feeding pins 6 on an endless conveyor I whose driving wheel 8 is geared to the platen 3 by gearing indicated diagrammatically at 9. The tabulating machine is provided with typing bars I0, which print a full line at one operation. As shown in Fig. 1, an electric switch Il is pro vided with a touch contact I2 and a spring contact I3, so that the circuit is closed automatically each time a typing bar I engages the stationery.

The carbon supply device has a main frame Ill, having an upright I and a guide frame I6, over which the printed forms travel from the platen and then drop into refolded relation in a pack Il. A series of carbon roll shafts I8 are journalled in the uprights I5, so that they may be removed to receive fresh carbon rolls I9. Each of the shafts is shown provided with a bevel gear 20, and these gears engage bevel gears 2| on a driving shaft 22 which is journalled on the frame I4, as indicated at 23. The lower end of the shaft is provided with a worm wheel 24, which is engaged by a worm gear on a shaft 25, provided with a ratchet wheel 26. An arm 2l is provided with a spring pressed pawl 28 to engage the ratchet wheel 26, and is urged downwardly by a spring 29. A solenoid 30 has a plunger 3l connected to the arm 27, and the solenoid is in an electrical circuit with the switch II, so that each time the switch is closed by a type bar the solenoid draws the arm 2l upwardly and imparts a partial turn to the ratchet 25. rThis in turn causes the carbon rolls I9 to turn counterclockwise, as viewed in Fig. 1, and permit a small amount of carbon strips Ita to travel forwardly with the stationery around the platen.

Preferably the ratchet wheel permits the carbon strips to advance but a small fraction of an inch at each operation, so that a very small amount of carbon is required to take care of the printing of a substantial length of stationery. It will be understood that the carbon strips are narrower than the lines of marginal perforations in the stationery, so that the carbon is not engaged by the pins 6. The worm carbon advances slowly and may be withdrawn from between the stationery from time to time by the operator, preferably while the stationery is passing over the guide frame I5.

The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations sho-uld be understood therefrom, for some modications will be obvious to those skilled in the art.

I claim:

In a line by line tabulating machine: a rotary platen and typing bars; an endless belt conveyor mounted above said platen and geared to move therewith, said conveyor having feed pins to engage marginal perforations in stationery strips and draw the stationery strips around said platen; a plurality of carbon rolls in rear of said platen from which narrow carbon strips may extend forwardly in interleaved relation with said stationery strips, said rolls being geared together; and step-by-step turning means for driving the carbon rolls in slower timed relation to the advancing stationery including a ratchet, a pawl, an actuating solenoid for said pawl, and an electric switch for energizing said solenoid and adapted to be operated by a. typing bar.

LOUIS JENSEN.

REFERENCES CITED The following references are of record in the le of this patent:

Number m Number 4 UNITED STATES PATENTS Name Date Kaser et a1. Nov. 3, 1914 Watson Nov. 14, 1933 -Sherman et al June 30, 1936 Hageman Oct. 27, 1942 Willard Dec. 25, 1945 FOREIGN PATENTS Country Date Switzerland 1925 

